Process of making inner tubes



June 25, 1929. GILLESPlE 1,718,646

PROCESS OF MAKING INNEfi TUBES Filed Jan. 20. 1926 2 Sheets-Sheet l m I F fie.

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June 25, 1929. R. GILLESPIE PROCESS OF MAKING INNER TUBES to methods for making the same, and .par-.

Patented June 25, 1929.

' UNITED STATES PATENT; I orrica';

Brennan L. GILLESPIE, or BARBER/role, onIo, Assmnon TO THE rmnsrroma TIRE AND. Runs-En COMPANY, or AKRON, OHIO, A CORPOR ATIOI\T oronro.

PROCESS OF MAKING INNER TUBES. C

Application filed January 20, 1926. Serial No. 82,464.

This invention relates to inner tubes and ticularly to the production of tubes with integral valve stems.

The general objects of the invention are to provide an improved inner tube construction wherein the valve is integral with the tube, to provide an improved procedure for making such tubes, and, in addition, to prov S-valves may be made.

vide a method whereby tubes with integral The foregoing and other objects are ob tained by the tube construction shown and the method illustrated in the accompanying drawings, and each more fully described below. It is to be understood that the inven-' tion is not limited to the specific form thereolshown and described.

, @t the accompanying drawings, I

Figure 1 illustrates a mandrel having a tube thereon andwrapped. in the manner it comes. from the vulcanizer;

s .Figure 2 is a radial section through the tube and mandrel at the valve, showing the green tube with the valve inserted therein before the wrappings have been applied;

Figure 3 is a similar view, showingthe completely vulcanized tube on the mandre' after removal of the wrappings; Y a

Figure 4 is a sideelevation of a section of broken away the tube at the 'valve, partly "showing the and partly in section, an

removable valve plate of the mandrel'which is, adapted to come on with the tube as the latter is stripped from the mandrel; and

Figure 5 is a radial section througha com plated tube at the valve. Referring to the drawin s, 10 represents a hollow mandrel," here' s own" of nearly closedC formation, for makin inner tubes olylarge sizes, but which may e a straight pole such as is employed in making tubes of smaller sizes. The mandrel 10 has therein on its inner periphery a circumferentially elongated slot as shown at 11 in which seatsa removable closureplate 12 having an aperture 13 therein, through which an inneratube valve ma pro ect.

The tu e is shown at 14 and is formed ot .raw vulcanizable rubber in any known manner'and applied to the mandrel 10;, closure 1 plate 12 being in place thereon. A valve aperture is punched;through the tube overlyin aperture 13 and .a valve reinforcing pate 15 is applied to the tube.

, narrow stri a Itwill appear from the andto bend the valveyinto S-sha e subsequent to vulcanization. The base oi valve 16 .is suitably treated as with athincoating of rubber cement 18 whereby it is adapted to vulcanize to the tube. The valve 16 isthen inserted into the tube through the aperture 13 on the mandrel into the position shown in Figure 2. i p 1 -Pressure 0n the tubeiduring 'vulcanizatign is obtained by wrapping the same with a t I of fabric 19 wound helically thereon; T e tube is so wrapped and together with others is inserted intoa suitable heater where it is vulcanized. vulcanization of the tube under pressure of the wrapper 19 causes the base 17 tobecome embedded in the tube as shown in Fi ure and the cementf18 permanently an integrally secures the ,valve to'the tube by vulcanization. v

After vulcanization, the wrapper 19 "is removed and thetuhe stripped'trom the mandrel, this latter step being accomplished in the customarymanner, the tubebeing turned inside out. Thus the smooth surface of the tube vulcanizedagainst the mandrel will be on the outside of the completed tube.

a In stripping the tube, closure plate 12 will come oil the mandrel therewith and the valve 16 will be drawn outwardly through slot 11 (see Figure 4 Plate 12 ma then be withdrawn from t 6 tube and rep aced in slot 11."

The valve 16 is given an-additional bend to form-it to'the desired S-shape as shown in Figure 5 and the ends of the tube are spliced in a known manner.

togetherand vulcanized to complete the tube foregoin that a tube has been provided which will e absolutely leak -proof at the valve and which requires no' threaded valve stem orinuts and clamps to securethe valve in the tube. The mushroom-shapedbase 17 on the valve 16 is such as to assume the general shape of the outersurface oi the tube during vulcanization (Figure 3) whereby a flat surface is avoided, pressure of the wrapper l9 thereon being equalized over its bottom convexv surface, thus insuring that the valve is properly embedded in the tube the rubber flowing about the outer edge oi the base (Figure 3) to securely interlock the base within the Wall of the tube.

Modifications of the invention may be resorted to without departing from the spirit thereof or the scope of the appended claims.

What is claimed is:

1. The process of making inner tubes with the preliminary shaping of thejlatter, molding and vulcanizing the tube so as to. embed the base of the valve in the wall thereof and finally bending said valve to S shape by forming a second bend therein.

2. The process of making innertubes with S valves, said process comprising providing a valve with a base and havin a single bend therein, treating said base so t at it will vulcanize to the soft rubber of the tube, inserting the valve in the tube during the preliminary shaping of the latter, moldin and vulcanizing the tube so as to embed t e base of the valve in the wall thereof and vulcanize it to the rubber thereon, and finally bending said valve to S shape.

3. The process of making inner tubes with S valves, said process comprising providing a valve with a base, inserting the valve in the tube durin thepreliminary sha ing of the latter, mol ing and vulcanizing t e tube so as to embed the base of the valve in the wall thereof, and finally bending said valve to S shape.

RICHARD L. GILLESPIE. 

